A dynamical study of the circumstellar gas in UX Orionis

Mora, A.; Natta, A.; Eiroa, C.; Grady, C. A.; Winter, D. de; Davies, John K.; Ferlet, R.; Harris, Alan W.; Montesinos, B.; Oudmaijer, R. D.; Palacios, Joaquín García; Quirrenbach, A.; Rauer, H.; Alberdi, A.; Cameron, A. Collier; Deeg, H. J.; Garzón, F.; Horne, K.; Merın, Bruno; Penny, A. J.; Solano, E.; Tsapras, Y.; Wesselius, P. R.

doi:10.1051/0004-6361:20021030

Cited by 26 publications

(32 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The only exception is HD 163296; its Na iD emission changed a factor ∼2 in one night (29-Jul.-1998), but no variations were detected the two following nights. We note that variations on timescales of hours have been reported for UX Ori using higher resolution spectra (Mora et al 2002). The typical EW(Na iD) in our sample is ∼0.40 Å.…”

Section: The Na Id Linessupporting

confidence: 64%

“…The spectroscopic monitoring of some sources (see e.g. Praderie et al 1986;Pogodin 1994;Rodgers et al 2002;Mora et al 2002Mora et al , 2004 revealed that the spectra of HAeBe objects are not only characterized by the presence of emission lines, but also by the complex variations observed in both the emission and absorption features. This variability is also characteristic of T-Tauri stars (see e.g.…”

Section: Introductionmentioning

confidence: 99%

“…The high temperature close to the stellar surface, which is generated in the accretion shock, has been suggested to be responsible for the He i5876 line (Tambovtseva et al 1999;Grinin et al 2001). Na iD lines seen in absorption describe the complex gas motions characterizing the CS medium around PMS stars (Mora et al 2002. A&A 529, A34 (2011) Most spectroscopic studies are based on isolated spectra of different sources or have been focused on particular objects.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Optical spectroscopic variability of Herbig Ae/Be stars

Mendigutía

Eiroa

Montesinos

et al. 2011

A&A

Self Cite

View full text Add to dashboard Cite

Aims. In order to gain insights into the variability behaviour of the circumstellar (CS) atomic gas, we have analysed 337 multi-epoch optical spectra of 38 Herbig Ae/Be (HAeBe) stars. Methods. Equivalent widths (EWs) and line fluxes of the Hα, [O i]6300, He i5876 and Na iD lines were obtained for each spectrum; the Hα line width at 10% of peak intensity (W 10 ) and profile shapes were also measured and classified. The mean line strengths and relative variabilities were quantified for each star. Simultaneous optical photometry was used to estimate the line fluxes.Results. We present a homogeneous spectroscopic database of HAeBe stars. The lines are variable in practically all stars and timescales, although 30% of the objects show a constant EW in [O i]6300, which is also the only line that shows no variability on timescales of hours. The He i5876 and Na iD EW relative variabilities are typically the largest, followed by those in [O i]6300 and Hα. The EW changes can be larger than one order of magnitude for the He i5876 line, and up to a factor 4 for Hα. The [O i]6300 and Hα EW relative variabilities are correlated for most stars in the sample. The Hα mean EW and W 10 are uncorrelated, as are their relative variabilities. The Hα profile changes in ∼70% of the objects. The massive stars in the sample (M * > 3 M ) usually show more stable Hα profiles with blueshifted self-absorptions and less variable 10% widths. Conclusions. Our data suggest multiple causes for the different line variations, but the [O i]6300 and Hα variability must share a similar origin in many objects. The physical mechanism responsible for the Hα line broadening does not depend on the amount of emission; unlike in lower-mass stars, physical properties based on the Hα luminosity and W 10 would significantly differ. Our results provide additional support to previous works that reported different physical mechanisms in Herbig Ae and Herbig Be stars. The multi-epoch observations we present are a useful tool for understanding the origin of the CS lines and their variability, and to establish distinctions in the physical processes operating in pre-main sequence stars.

show abstract

Section: The Na Id Linessupporting

confidence: 64%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Optical spectroscopic variability of Herbig Ae/Be stars

Mendigutía

Eiroa

Montesinos

et al. 2011

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…These features are also seen in other Herbig Ae/Be stars such as UX Ori, BF Ori, SV Cep, WW Vul, and XY Per, see e.g. Mora et al (2002Mora et al ( , 2004 and references therein. These features are called transient absorption components (TACs) because they are sporadic in nature and last for a few days only.…”

Section: Hα Line Profilesmentioning

confidence: 61%

“…Natta et al (2000) reported the evidence for episodic rather than continuous accretion in Herbig Ae star UX Ori. Mora et al (2002Mora et al ( , 2004 reported transient absorption components (TACs) in several Balmer and metallic lines of a few Herbig Ae type stars, which are supposed to be created by moving gaseous blobs around these stars. These studies discussed the dynamical circumstellar environment around Herbig Ae/Be stars which show strong Hα emission.…”

Section: Introductionmentioning

confidence: 99%

Variable circumstellar activity of V351 Orionis

Choudhury

Bhatt

Pandey

2011

A&A

View full text Add to dashboard Cite

Context. Emission and absorption line profiles which are formed in the interaction of pre-main sequence stars and their circumstellar environment are found to be variable at various timescales. Aims. We investigate the patterns and timescales of temporal line profile variability in order to explore the dynamical circumstellar environment of the pre-main sequence Herbig Ae star V351 Ori. Methods. We obtained 45 high-resolution (R ∼ 28 000) spectra of V351 Ori at timescales of hours, days, and months. We analysed the Hα line profiles and also examined the Hβ, NaD1 and NaD2 line profiles to explore the nature of the spectroscopic variability. Results. The Hα line profiles showed strong variations over all timescales. The shape of the profiles changed over timescales of a day. Single as well as simultaneous event(s) of blue-shifted and red-shifted transient absorption components, i.e. signatures of outflow and infall, were also observed in the Hα line profiles. The shortest period of variation in the transient absorption components was ≤1 hour. All transient absorption events were found to decelerate with a rate of a few to fractions of m s −2 . The depth and width of the transient absorption components were also changing with time. The presence of elongated red-shifted components at some epochs supports the episodic nature of accretion. Conclusions. Variable emission and absorption components detected in Hα line profiles show the dynamic nature of interaction between V351 Ori and its circumstellar environment. The Hα non-photospheric profiles of the star most probably originate in the disk wind. Episodic accretion of gaseous material at a slow rate and outflow of clumpy gaseous material are still occurring in V351 Ori at an age of ∼6.5 Myr. Dynamic magnetospheric accretion and disk wind emerge as the most satisfactory model for interpreting the observed line profile variations of V351 Ori.

show abstract

An Introduction to Accretion Disks

Alécian

2013

The Environments of the Sun and the Stars

View full text Add to dashboard Cite

A dynamical study of the circumstellar gas in UX Orionis

Cited by 26 publications

References 22 publications

Optical spectroscopic variability of Herbig Ae/Be stars

Optical spectroscopic variability of Herbig Ae/Be stars

Variable circumstellar activity of V351 Orionis

An Introduction to Accretion Disks

Contact Info

Product

Resources

About